The Surrays and their five children form a prolific writing machine, with scores of treatises, reviews, and crime thrillers published under their family name. Following a rare convergence of the whole household at their Oxfordshire home, Ruth—middle sister who writes "books which are just books"— decides to spend some weeks there recovering from the pressures of the writing life, while the rest of the brood scatter to the winds again. Their next return is heralded by the tragic news that Ruth has taken her life after an evening at the Surrays's hosting a set of publishers and writers, one of whom is named as Ruth's literary executor in the will she left behind.

Despite some suspicions from the family, the verdict at the inquest is suicide—but when Ruth's brother Richard receives a letter from the deceased which was delayed in the post, he enlists the help of CID Robert Macdonald to investigate what could only be an ingeniously planned murder.